


Night Shift

by tadayamas



Category: Haikyuu!!
Genre: Alternate Universe, Alternate Universe - Different First Meeting, Astronomer Yamaguchi Tadashi, First Meetings, Flirting, Fluff, Getting Together, M/M, Misunderstandings, Mutual Pining, Night At the Museum AU, One Shot, Security Guard Tsukishima Kei, Yamaguchi Tadashi's Freckles, suga makes an appearance
Language: English
Status: Completed
Published: 2021-02-05
Updated: 2021-02-05
Packaged: 2021-03-17 01:07:35
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,813
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29216931
Author URL: https://archiveofourown.org/users/tadayamas/pseuds/tadayamas
Summary: Night at the Museum AU in which Tsukishima runs into a very pretty astronomer while trying to escape a T-Rex.
Relationships: Tsukishima Kei/Yamaguchi Tadashi
Comments: 22
Kudos: 116





	Night Shift

**Author's Note:**

> I'm so sorry but none of the actual NATM characters make an appearance except Rexy, as much I wanted to add Jehediah and Octavius it would've made this much longer than I intended :')
> 
> Also, the interior of the museum is loosely based on the museum in the movie bc I know it can fit a dino fossil, but the exterior is based on the Sendai Museum bc who is Tsukki if not an employee at Sendai Museum specifically. (the exhibition room is based on nothing but my imagination so have fun!)
> 
> Sorry for any mistakes and enjoy <33

_ No no no no no…  _ Kei thought as he watched the skeleton of a tyrannosaurus-freaking-rex shake and sketch out like a dog getting ready to play. He kept his eyes on the spontaneous miracle of life as he attempted to slide quietly to the nearest way out of the main hall of the museum. The t-rex moved its skull to face him.  _ There’s no way it can see me.  _ Kei was close to a walkway now, the T-Rex still tracking him, head bowed and back arched like it was…

“Shit—” Kei leapt toward the exit and began sprinting just as the skeleton jumped for him. It crashed against the walls as it barrelled after him. 

He could hear it’s footsteps stomping somewhere behind him, quickly nearing. He needed to get somewhere with a lockable door and fast. But trying to examine his surroundings at night while running from an actual dinosaur was not ideal. He barely caught the sign pointing toward the planetarium. 

Breaking left, he made his way into the unfinished space exhibition. He’d been there during the day, the director explaining they just needed to finalise some details before opening it to the public. He’d taken note of the  _ Explorers Through Time _ section that had wax figures of various icons of space exploration, each covered with a sheet— “To keep the dust off for now,”— and projection of constellations displayed on the wall behind them. If he was going to need a room to hide from an animated fossil, it might as well be this one. 

Kei swiped his security card at the door and slipped through, making sure to close and lock it securely. ( _ Lockable, check. _ ) He breathed a sigh of relief, pausing to get his breath back. He could deal with ancient magical tablets and unreasonably attractive pharaohs, he could deal with tiny cowboys and Romans trying to kill each other, he could deal with a talking Easter Island statue; hell, he’d been having a lovely conversation with some painting earlier. But a  _ dinosaur _ ? Kei would be excited if it wasn’t a sure-fire way to die on the job. 

“Um, excuse me?”

Kei whipped around to face the new voice and was met with— constellations? Oh, freckles. And dark green hair, and wide brown eyes, and- 

“Are you okay?” The man in front of him peered at Kei, worry etching his forehead. Kei shook his head.

“Uh, yes. Yeah, I was just— running. From— uh—”

“The T-Rex?” The stranger smiled gently. 

“Yeah,” Kei sighed. 

The stranger laughed and Kei thought he heard bells ringing. “Well, I think we’re safe in here! Galileo told me about Rexy earlier. I was going to go say hello, honestly—” He laughed again, “—but, looking at you, I think staying away is the better option, yeah?” 

Kei hummed as the stranger stepped forward, poking his ID badge. 

“…Tsukishima, nice name! I’m Yamaguchi Tadashi.” 

“Nice to meet you, Yamaguchi.” Kei paused. “…Did you say Galileo?”

— 

Yamaguchi told Kei he was an astronomer, that he worked with the city’s top university, that he helped discover a star cluster that had never been seen before thanks to newly developed technology. He looked so passionate when he spoke that Kei almost believed he was a real, living person and not just a magically animated wax statue. Yamaguchi, Kei guessed, represented the Modern Day Astronomer in this exhibition and Kei wanted so badly to be able to take him out to the mountains to see the actual stars, not just the projections on the museum walls. 

Yamaguchi seemed to glow under the shimmering lights of the planetarium as he talked about his manufactured passion. Absently, Kei wondered how many other Yamaguchis currently existed across Japan, housed away in storage waiting for their own exhibition, never to exist in the uniquely magical space that was Sendai Museum. He wondered, if brought to the museum, would they sound the same as this Yamaguchi? Would their smile curl the same way as they spoke, if their laugh was as gentle or if—

“—I mean this is my first exhibition, too! It’ll be so nerve-wracking to face so many people on opening day, I can’t imagine how… um, Tsuk— Tsukishima?”

Kei blinked, reverie interrupted. “I’m listening.” 

Yamaguchi laughed, head knocking back against the wall they were sitting against. He really liked to laugh, Kei noticed, watching the freckles around Yamaguchi’s eyes crease together. 

“Ah— no it’s just—” He laughed again— “You looked like you were studying for a test or something! So focused, Tsukki.” He giggled quietly again and Kei nearly missed the last part of what Yamaguchi said. 

“Tsukki?” Kei allowed himself to blush at the thought of Yamaguchi liking him enough to give him a nickname. 

“Oh!” Yamaguchi reaches a hand up to the back of his neck, twisting his hair sheepishly. “Tsukishima was kind of long, and we’ve been talking for a little while now, I thought it would be alright if—”

“Tsukki is fine.” Kei watched as Yamaguchi’s fingers stilled their hair-twisting, “But,”—twist, twist, twist—“I think it’s only fair if I can call you something too.” Kei smirked at the darkening of Yamaguchi’s cheeks. 

Yamaguchi coughed, “Ta— Tadashi is fine, Tsukki.” 

The two shared a smile, warmth bubbling within their chests.

—

Hours later— or minutes, really. Kei noticed time seemed to bend and sway while he talked to Tadashi— one of the Greek statues knocked on the door to inform Kei that Rexy had settled down, and if he could stop the miniature cowboys from exploding the miniature Romans’ display once again, that would be most helpful, thank-you, Tsukishima-san. 

One of the good things about working in a museum full of animated, free-thinking art pieces and wax figures is that most of them had a mind to  _ not  _ destroy their surroundings. The miniature cowboys and Romans, however, did not share that sentiment. 

Kei looked at Tadashi, who was fiddling with the sleeves of his button-up, frowning. 

“Tadashi—”

“Will I be able to see you again? It’s getting pretty late— or, early, I guess. We’ll both have to go soon, won’t we?”

Kei paused, “Probably… won’t you be here tomorrow night too?”

Tadashi shrugged, brow scrunching, “I don’t think so. I don’t usually hang out here at night like you, Tsukki.”

_ Do they keep him in storage? _ “I’ll come back before my shift ends. See you, Tadashi.” 

Kei made his way to the exit, looking back to where Tadashi sat. Tadashi met his eyes and smiled, causing Kei’s face to heat up. He nodded slightly before following the statue out into the corridor. 

— 

By the time Kei was able to convince the miniatures that the dynamite crates they were using were, in fact, fake and made out of plastic, it was nearing the end of his shift. Which meant it was almost sunrise, which meant Tadashi was probably going to freeze up again and he wouldn't be able to see him until his next shift. 

Kei, at the moment, was definitely not sprinting down a corridor filled with priceless artefacts at that thought. 

He was, however, walking rather briskly. 

“Tadashi!” Kei pushed open the door of the planetarium to see the other wax figures moving back to their places in the display. Kei scanned them looking for dark hair and freckles—

“He went home, son.” One of the astronauts spoke up from his stand. Kei blinked. 

“Home?” Was Tadashi not part of this display?

The astronaut nodded, scratching his chin thoughtfully, “Yeah, ‘said he had to run since it would be bad if he were caught up here, so he went home.”

_ Oh, he left storage _ . Tadashi the curious astronomer, leaving his crate at night to see the stars. Kei laughed gently,  _ makes sense. _

“Noted. It would probably be bad if they found him here earlier than expected.” Kei thanked the figure, who nodded solemnly.

“That it would, son. That it would.” 

Kei left the planetarium, something heavy in his chest.

—

Rexy the T-Rex wiggled in place as Kei made his final lap of the museum. Kei eyed the Tyrannosaurus as he circled it from as far as possible. It turned its skull to him. 

“Don’t you dare,” Kei jabbed at the air in front of him. “I don’t wanna deal with this right now.”

Rexy seemed to settle at Kei’s words.  _ It really is like an oversized dog… _

“…Good boy?”  _ There’s no way that would— _

The fossil sat exactly like a well-trained dog, head up and alert, giant tail wagging slightly behind its bony body. 

Kei crept toward the front desk where his bag was kept, picking it up gently. He held a hand out toward Rexy as he continued his trek to the doors. 

“Stay…stay…good dinosaur….”

The sun was almost up. He opened the door just as Rexy returned to its original pose and stilled, all signs of animation leaving its bones. 

What a night.

—

Kei was running down the street at eight am in the morning. The  _ same  _ morning.

_ I’m a nightguard, not a twenty-four-seven, call-me-anytime guard.  _

He scowled, feeling the steady thud of his sneakers as he followed the path to the museum. 

_ I better get overtime for this.  _

—

Kei barrelled through the museum entrance at ten-past-eight am; early. He was greeted by his supervisor and a large to-go latte.

“Ah, Tsukishima! You’re here, thank god!” Suga-san shoved the coffee cup into Kei’s hands, “I know it’s a little short notice—”

“An  _ hour,  _ Suga _ — _ ”

_ “— _ Apology coffee, drink.” Kei took a sip, scowling at how good it tasted. His supervisor continued, “As I was  _ saying _ , I know it’s  _ very  _ short notice. You’ll be needed for three hours. Thank you for coming in, Tsukishima, you were literally the last person I called. You know how it is, for such a—”

“ _‘For such a large museum, we sure are understaffed.’_ ” Kei rolled his eyes, “Yeah, I get it, Suga-san.” 

Suga-san laughed at him. Kei couldn’t understand how that man stayed chipper so early in the morning. He took another sip of the drink. 

“Where am I headed, again?” 

Suga-san bounced on his heels and started leading the way, “Well, the change room first; we can’t have you in joggers and a sweaty uh… sweater. Then go to the Planetarium, I think you’re there for a special guest or something.”

Kei nodded, refusing to react to the “sweaty” comment. The last part, though, caught his attention. He turned to Suga-san, “Special guest?”

Suga-san faced him, “Apparently someone from the university is coming in to give a presentation… how exciting!”

“Hm.”

They stopped in front of the staff rooms. Suga-san swiped his card and ushered Kei into the change room, “Okay, thanks again for coming in, Tsukishima! Have fun, I’ll make sure you aren’t on for tonight too. Bye-bye…” 

The door shut behind Suga-san on his way out. As Kei began changing into his uniform, he felt a seed of hope begin to bloom. He’d be seeing Tadashi the Astronomer. He knew Tadashi would be frozen in time, but at least he’d be able to see him sooner than he thought. 

Kei changed in record time.

—

The exhibition wouldn’t be open to the public for another half hour, along with the rest of the museum. Kei stood by the corner closest to the  _ Explorers Through Time  _ section, watching as the day staff made last-minute adjustments around the exhibition. Now lit up and unveiled, Kei could now see the rest of the room in all its glory. 

Constellations glittered across the rounded walls and the large, blacked-out ceiling. The room was glowing with slowly rotating blue and purple lights, contrasting the magenta nebula display glittering at the far end of the hall. He could make out the faint sounds of pink noise and “bright synths'' flowing together to create a space-like ambience. It seemed to be working. Not that Kei would admit he finds anything branded as “space music” relaxing. In the centre of the room, a scale model of the Apollo 11 lunar module was positioned, the floor had been replaced by, what Kei assumed, was a loose interpretation of the surface of the moon. Apparently white sand is an accurate substitute for moon dust.  _ A for effort, I guess.  _

Kei scanned the employees of the room, acknowledging the other guards in their own positions. By the entrance, Kei noticed the way the director was pacing, checking her watch every few seconds.

“Uh—”

“Yes, Tsukishima?” Yachi Madoka looked to Kei and, for a second, Kei felt like he was suddenly a twelve-year-old who had stumbled into an out-of-bounds area on a school field trip. He steeled himself. 

“You seem worried, Yachi-san. I was wondering if there was anything I could assist with.”

Yachi-san paused for a moment, seeming to consider Kei's offer, to his surprise. “Hmm. No, thank-you, Tsukishima. Unless you can go find—”

“I’m here!” A young man barrelled through the entrance door, stumbling slightly as he stopped in front of the director. “Yachi-san, I’m here! I’m so sorry, I lost track of time and—”

“Don’t mind, Yamaguchi-san. We’re still fifteen minutes until opening, you’re technically on time…”

Kei stopped paying attention as soon as he heard the name “Yamaguchi” leave the director’s mouth. All he could focus on was the dark green hair of the new-comer, neatly pulled into a ponytail, the smattering of freckles adorning his flushed cheeks. If this Yamaguchi looked his way, Kei would be willing to bet his eyes would be the same hazel colour as wax figure Yamaguchi.

Yamaguchi was a common name, wasn’t it? Kei was hallucinating, he decided. There’s no way Tadashi the Astronomer was standing less than ten feet away from him at eight-forty-five, during the  _ day. _

“… And Tsukishima here will be working as security for the hours you’re scheduled to give presentations, so if you feel uncomfortable at all just let him know. Isn’t that right, Tsukishima?”

Kei nodded, suddenly very aware that Yamaguchi was looking at him with those same hazel eyes, “Yes that’s correct. I’m here to keep you safe, Yamaguchi-san.” 

Yachi-san looked satisfied with his answer, “Excellent. I’ll leave you both to it. Do your best, Yamaguchi-san.” 

And with that Yamaguchi the guest and Tsukishima the security guard were left alone in their little corner of space. Yamaguchi was staring directly at him and Kei kind of wanted to melt into a puddle of space-themed goo. 

“Tsukki?” No way. “Tsukki, I didn’t know you’d be the guard today, I thought—”

“There was a change of plans. Very last minute. I, uh— I didn’t know either, Yamaguchi-san.” Yeah. Keep it professional, Kei. Great Idea. 

Kei looked at Yamaguchi. He was frowning. Shit.

“Uh— not that I’m not happy to see you again—”

“‘Yamaguchi-san?’ Should I call you ‘Tsukishima-san’ too? This is your job, right? Talking on a first name basis would be a bit strange...” Yamaguchi (Tadashi? Kei’s mind was spinning), tapped his chin in thought, “Tsukki-san! How’s that?” 

Kei stared, trying so hard to process the last five minutes. “Ye—yeah. Sounds good, Yamaguchi-san.”

Yamaguchi smiled, and Kei was convinced he was dreaming, “Look after me, Tsukki-san!”

—

Two hours. Two whole hours Kei had been watching Special Guest Yamaguchi Tadashi make small presentations around the exhibition space. Two hours Kei hadn’t been able to not look at Special Guest Yamaguchi Tadashi, who was very much in his element. Two hours for Kei to come to terms with the fact that Yamaguchi Tadashi was very much  _ real  _ and  _ not  _ a magically animated wax figure.—One glance at the display definitely confirmed that; there wasn’t even spot where Yamaguchi Tadashi, the modern space explorer, could’ve been positioned. Kei wanted to travel back ten hours and kick himself. 

Right now, Yamaguchi was nearing the end of another presentation, answering the questions of a group of curious school children as earnestly as possible. Kei watched as the children said their good-byes to the astronomer, each filling out of the hall as organised as a bunch of seven-year-olds can. Yamaguchi waved back at them, a bright smile plastered across his face. Kei watched as the lights danced across Yamaguchi’s freckled cheeks.

About half an hour into his shift, Kei had noticed that a few of Yamaguchi’s freckles resembled the constellations projected onto the night sky ceiling of the exhibition. Kei wondered if Yamaguchi had ever been told that he has Pisces across his left cheek.

“Tsukki-san!” Yamaguchi was walking towards him, still smiling. Kei felt his breathing falter.  _ Pull it together.  _

“Yamaguchi-san. Is everything alright?” 

“Yep!” Yamaguchi was standing at Kei’s shoulder now, hands held politely behind his back, leaning into Kei’s space slightly. Kei could smell his cologne. Something sweet he couldn’t place, but still distracting. Kei had always liked sweet things. 

“That’s good to hear.”

Yamaguchi nodded in agreement, bumping their shoulders together, “Hm, yes. Hey, Tsukki, I’m only here for about another hour.” 

Kei raised an eyebrow, looking down to where their shoulders had gently connected. 

“Is that so?”

“Mhm. Thought you might want to know. For business reasons or something.” Yamaguchi seemed very interested in looking anywhere but Kei right now.

Kei acquiesced, “Business reasons?”

“Or something.” 

“Or something, huh?” 

“Yep.”

“Thank you for that important information, Yamaguchi-san.” Kei decided it was his turn to bump their shoulders together, “My shift ends in an hour, too. For business reasons.”

“Or something?” A shy smile had crept up Yamaguchi’s face, he pressed his shoulder back into Kei’s holding for a second. 

Kei pressed back, “Or something.”

Yamaguchi shot him another blinding grin before heading back to a new group waiting by the entrance. 

—

At five-past-twelve pm, another guard walked into the exhibition, signalling that Kei was officially allowed to leave. Yamaguchi had already left at twelve.

“I’ll wait for you,” he had said in passing.

Kei rushed through getting changed out of his uniform and into the spare set of jeans and sweater he had jammed into his bag that morning, knowing he wouldn’t want to return home in the same joggers he arrived in. He walked as fast as he could through the lobby and stepped out onto the front steps, scanning the area for green hair. 

For a moment, Kei thinks that maybe he had let himself hope too much; that Yamaguchi was some miracle that existed solely inside the museum and upon stepping outside, he had faded away, never to be seen again. Kei’s chest ached with the thought, maybe it really wasn’t meant to be—

“Tsukki!” Kei turned to his right to see Yamaguchi Tadashi sitting atop the rounded concrete bench, waving at him cheerfully. 

Kei approached him steadily, trying to take in the way the sun poured down upon Yamaguchi’s hair, making it shimmer in different shades of brown and green. Yamaguchi had smiled at him so many times in the few hours they’ve spent together but, in that moment, Kei decided he’d do anything to keep Yamaguchi smiling at him like that. Kei stopped in front of Yamaguchi, who had risen from his perch to meet him in the metaphorical middle. He’s real. Yamaguchi is one-hundred per cent a living and breathing human person who’s standing in front of Kei, opening his mouth to say something and Kei is so ready to listen to whatever he has to say.

“So— ”

“You’re real.” Kei slapped a hand over his big, stupid mouth.  _ I did not just say that. _

“Uh? Yes. Tsukki. Yes, I am real,” Kei didn’t miss the way Yamaguchi’s face scrunched in confusion. The ground seemed very interesting to Kei right now. Yamaguchi continued, “I was going to suggest we get coffee? Maybe? That’s a real person thing to do when you like someone, right?” 

Kei jerked his head up, “Are you teasing me?” 

Yamaguchi pretended to ponder the question, “Hmm, I don’t know, Tsukki. Why don’t you get lunch with me and find out.” Kei was struck with another Yamaguchi-issued grin. Kei smiled back. 

“Coffee sounds good, Yamaguchi.”

“Yes!” Yamaguchi fist-pumped and Kei found it embarrassingly endearing. 

He held out his hand for Yamaguchi to take, “There’s a cafe a few minutes from here.”

Yamaguchi intertwined their fingers, “Awesome! Also,” He looked back to Kei, “you can call me Tadashi— uh— if you want to. No pressure or anything!” 

Kei noticed Yamaguchi had lifted his free hand to the back of his head, twisting a strand from his ponytail. 

“Alright, Tadashi. You can call me Kei, if you like.” 

The hand stopped twisting. Tadashi seemed to glow momentarily, “Okay, Kei!” He began walking, pulling Kei along, “Maybe on the way you can tell me what that ‘You’re real’ thing was about,” he laughed.

Kei laughed with him.

—

“I’m sorry— can you— re— repeat that a—again,” Tadashi was doubled over on Kei’s couch, a week after their impromptu lunch date, crying from laughter. Kei sat beside him, head in hands, groaning.

“I thought you were one of the wax figures,” He mumbled, slouching into the couch further. Maybe if he tried hard enough, the couch would accept him as one of the pillow people and grant him entrance into couch land. That way he wouldn’t have to deal with the immense humiliation of thinking his now-boyfriend was a magically animated figure designed to be part of a month-long exhibition. 

“HA—” Tadashi was cackling now, revelling in Kei’s despair.  _ This  _ was why he had opted to wait until they were  _ alone  _ to tell Tadashi his exact reason as to why he was surprised that the astronomer was, in fact,  _ real.  _

“Kei— Kei— oh my god, I’m so sorry— ” Tadashi’s apology was interrupted by yet another round of giggles. 

Kei huffed, “Yeah, yeah. My misery is hilarious, I know.” 

Kei peeked over his hands to see Tadashi sprawled out on the rest of the couch, almost falling onto the floor, head buried in a throw pillow to muffle his hysterics. Kei appreciated the sight of Tadashi’s flushed face, scrunched with mirth and the sound of his laughter filling the apartment, before grabbing a pillow from his side and slamming down onto Tadashi’s vulnerable stomach, grinning. 

“ _ OOF! _ ” Tadashi’s arms came down to clutch the plush weapon, “Betrayal!” 

Kei pushed the pillow down, laughing at Tadashi’s dramatics.

“Kei, my love, I’ll never laugh at your lack of critical thinking again, I promise!” 

“I don’t know…” He moved to prop himself on the pillow, gazing at Tadashi, who peered back, trying (poorly) to suppress a smile. “How do I know you’re being honest?” 

Tadashi thought for a moment, lips pursing. “I’ll buy you cake?”

“Deal. Let’s go.” Kei started moving off the couch. 

Tadashi sprung up easily, “Okay! More for you since wax figures don’t eat, I suppose.”

Kei squinted at his dear, darling Tadashi, who was trying his very best to look the picture of innocence. “You’re never letting it go, are you?”

“Nope!” Tadashi grabbed his jacket, “Let’s get cake!”

**Author's Note:**

> You made it! Thank you for reading, I hope you had fun :) let me know your thoughts!! 
> 
> come say hello to me on [twitter](https://twitter.com/lesbiantsukki) where I post art and other tskym-related content <33


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